Roasting-furnace



`H. ALINDER.

HOASTING FURNACE. APPLICATION FILED APR. 2, |917- 1,332, 152. Patented Feb. 24,1920.

2 SHEETS-SHEET l.

H. ALINDER.

ROASTING FURNACE.

APPLICATION FILED APR. 2. 1911.

1,332,152. Peeented Fem/1,1920.

2 SHEETS-SHEET 2.

-the main shaft, at minimum cost of con- VUNITED STATES PATENT OFFICE.

HENRY ALINDER, OF MILWAUKEE, WISCONSIN, ASSIGNOR T0 AIIIS-CI-IALMERS MANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN7 A CORPORATION OF DELAWARE.

ROASTING-FURNACE.

Specification of Letters Patent.

Patented Feb. 24, 1920.

Be it known that I, HENRY ALINDER, a subject of the King of Sweden, residing at Milwaukee, in the county of Milwaukee and `State of lVisconsin, have invented a certain new and useful Improvement in Roasting- Furnaces. of which the following is a specification.

This invention relates to improvements in the construction of lore roasting furnaces and has particular relation to improvements in that class of devices known as Mc- Dougall furnaces.

An object of the invention is to provide a roasting furnace which is simple in construction and efficient in operation. One of the more specific objects is to provide means whereby the rabble arms of a roasting furnace of the McDougall type, may be readily inserted in and removed from the furnace, from the exterior thereof, thereby permitting insertion or removal of the arms without necessitating cooling down7 of the furnace. another object is to provide means Jfor fastening the rabble arms to the main shaft, which are simple in construction, efficient i-n operation and which may be readily manipulated. A further object is to provide means for effectively cooling and insulating the furnace elements which are normally subjected to excessively high temperatures. Still another object is to provide means for inducing an eticient flow of cooling medium through the main shaft and rabble arms of a fur-nace. A further object is to provide effective insulating means for struction and having minimum weight. A further object is to provide a mounting for the main shaft which will accommodate itself for deflection or warping of this shaft, due to the high temperature in the furnace.

A clear conception of an embodiment of the invention may be had by referring to the drawings accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views.

Figure 1 is a transverse vertical section through a six-hearth McDougall furnace having yfeatures of this invention apphed thereto.

Fig. 2 is an enlarged fragmentary central vertical s'ection through the fourth and fifth hearths of the furnace disclosed in Fig. 1. l Fig. 3 is an enlarged central vertical section through one of the rabble arms showing the same applied to a fragment of the main shaft.

Fig. 4 is an enlarged fragmentary transverse horizontal section through one of the rabble arms and main shaft, the section being taken along the line IV--IV of Fig. 5 looking in the direction of the arrows.

Fig. 5 is an enlarged end View of one of the rabble arms showing the same applied to a fragment of the main shaft and showing in dot and dash lines, the position of the locking bar during removal or insertion of the arm.

Fig. 6 is an enlarged transverse vertical section through the lower universal bearing of the main shaft.

The McDougall furnace disclosed in Fig. 1, comprises a drying bed, six superposed roasting hearths d located below the drying bed, and means for urging material over the drying bed and through the successive hearths 4. The hearths 4 are inclosed at the sides by means of a circular outer wall '7 provided with the usual inspection openings v('32, and supported upon suitable sub-structure 24. The upper hearth 4t and the drier bed are separated by an upper wall 11 provided with feed openings 52. The successive. hearths il are separatedby means of substantially horizontal walls, some of which are provided with central openings 5 and others of which are provided with peripheral openings 6. The lower hearth is provided with a lower wall 8 formed with discharge openings communicating directly with the discharge hoppers 9. The upper hearth 4.- is provided with gas discharge conduits 10 of usual construction.

The means for urging or conveying the material over the drying bed and through the successive hearths, comprises a vertical main shaft 1, drier rabble arms 12 provided with adjustable rabbles 13, and rabble arms 2 provided with rabbles 3. The rabble arms 12 are located adjacent the drying bed, while the rabble arms 2 are arranged in pairs within the successive hearths 4. in the usual manner. The main shaft 11 is supported centrally within the wall 7 by means of an upper bearing 14: and a lower universal bearing which is mounted upon a suitable foundation 21. Suitable sand packings 50, 51, of usual construction are provided bctween the main shaft 1 and the walls 8, 11, respectively. The main shaft 1 is provided at its lower extremity with an air chamber 17 communicating through openings 18 with the air inlet pipe 16. The main shaft 1 is rotatable by means of suitable power applied to a drive pulley 23 which transmits motion through gearing 22 and bevel gears 20, 19 directly to the lower end of the shaft 1.

The furnace at its upper extremity, is provided with a feed plate 57 upon which the material to -be treated is deposited and from which this material `is gradually delivered upon the drier bed by means of a feed cam 58 operated directly by the main shaft. The drier rabbles 13 are adapted to convey the material delivered upon the drying bed by the cam 58, outwardly and to discharge the same into the upper hearth of the furnace through the openings 52. The rate of feed of the material may be varied by adjustment of the drier rabbles 13, such adjustment being effected by means of the rabble stems 55 and the clamping devices -56.

The lower portion of the main shaft 1, which passes through four lower hearths 4 of the furnace, is provided with a mantle 25 formed of fire brick, asbestos or other insulating material. The portion of the main shaft which extends through the two upper hearths is not insulated. A suitable guard 26 prevents material from falling into the space between the upper end of the mantle 2,5 and the adjacent division wall. Suitable packings of usual construction are provided between the main shaft 1 and the adjacent division walls between the hearths 4.

The main shaft 1 is provided with an inner conduit 28 and an outer annular conduit 27 communicating with the inner conduit 28 through passages 31, 30 formed in the arms 2, see aFigs. 2, 3 and 4. The inner conduit is formed by relatively light pipe sections suspended from the walls of the shaft'l by means of ribs 37. The inner conduit 28 communicates directly with the chamber 17 at the lower end of the main shaft l, this conduit 28 being closed at its upper end. The outer conduit 27 is closed at. its lower extremity and communicates with a damper controlled discharge opening at the upper end of the main shaft 1. The .arms 2 when in normal position have their conduits 31 communicating with the shaft conduit 28 through openings 36, the arms 2 abutting the wall of the conduit 28 adjacent these openings.

The main shaft 1 is rovided with bosses 29 which are bored to t the inner ends of the rabble arms 2. The rabble arms 2 are provided with longitudinal partitions 32 which divide the arms into the conduits 30, I

3l. Each conduit 30 has therein a transverse rib 59 which is provided with a screwthreaded through-opening within which is located the threaded rod 34. The threaded rod 34 has mounted thereon a locking element 33, which is detachably secured to the rod by means of a nut 39 and cotter pin 40. The element 33 is urged against the nut 39 by a helical compression spring which reacts against a collar on the rod 34. The inner ends of the arms 2 abut projections or stops 38 formed on the shaft 1 adjacent the inner ends ofthe bosses 29, The locking elements 33 are manipulated through the outer ends of the arms2 by means of a socket wrench 35 adapted to engage the ends of the threaded rods 34. Guiding surfaces 61 serve to guide the socket of the wrench 35 onto the ends of the rods 34. The outer ends of the rabble arms 2 are normally closed by means of removable caps 53 provided with locking lugs 54 engaging cam surfaces formed adjacent the ends of the arms 2. The locking elements 33when in locking position abut the stops 60 formed on the arms 2, and when in position permitting removal of the arms 2, are disposed'as disclosed in dot and dash line in Fig. 5.

The lower universal bearing 15 comprises a bearing' casing 41, spherical side shells 42 engaging' the casing 41 and provided with babbited linings 46 engaging the shaft 1, and a spherical lower shell 43 disposed between the lower end of the shaft 1 and the lower bearing' element 44. The casing 41 and element 44 engage the bearing supporting plate 45 which is mounted upon the bearing foundation plate 48. Lubrication of the bearing surfaces is effected through a lubrication inlet 49 and foreign mattei' is prevented by a dust guard 47 from entering the bearing.

During the normal operation of the fui'V nace the material to be treated is fed upon 4the drying 'bed by means of the rotating cam 58 and is gradually distributed over this bed, by means of the rabbles 13, being' preliminarily heated during its passage over the bed and being eventually' delivered into the upper furnace hearth through the openings 52. In the upper hearth the material is gradually conveyed inwardly toward the main shaft 1 by means of the rabbles 3 .carried by the rabble arms 2, being eventually delivered into the hearth 4 below, through the central opening 5. The material thus delivered through the opening 5 is fed outwardly toward lthe openings 6 by means of the rabbles 3, being' eventually delivered through the openings 6 into the hearth 4 below. The material is thus fed through the successive hearths 4, being automatically roasted as it passes through these hearths and being finally delivered from the furnace through the discharge hoppers 9.

In order'to prevent injury to the rabble arms 2 and the central shaft 1 due to the high temperatures, air is permitted to flow through the conduits 28, 31, 30, 27, thereby cooling the arms 2 and the shaft 1. As the temperatures in the lower hearths of the furnace are relatively high, and in order to prevent these excessive temperatures from injuring the main shaft 1, the sectional fire brick mantle 25 is provided. Due to the fact that the temperatures in the upper hearths are comparatively low, so that the heat in these hearths will not materially affect the main shaft, the fire brick mantle 25 is omitted within the upper hearths. By thus omitting the mantle 25, the air leaving the furnace through'the conduit 27, is additionally heated, thereby inducing a greater flow of air through the lower portion of the shaft 1 and the adjacent rabble arms 2. By omitting the fire brick mantle in the upper hearths, the weight of the mantle, as well as the cost thereof, are also materially reduced. The gases of combustion generated in the successive hearths of the furnace are discharged through the openings 5, 6 and the conduits 10 adjacent the upper hearth il.

In order to permit insertion and removal of the rabble armsv 2, without cooling down the adjacent hearths, inspection openings 62I are formed in the furnace wall 7, there being several of these openings for each hearth. The arms 2 may be removed by removing the caps 53 and inserting a socket wrench as disclosed in Fig. 3, in order to release the locking element 33. By turning the threaded rods 34, the locking elements 33 may be released and swung into such position that they lie entirely in line with the openings through the bosses 29, as indicated in dot and dash lines in Fig. 5. With the lockingelements 33 thus positiene-d, the corresponding` arms 2 may be readily withdrawn from or inserted in the bosses 29 from the exterior of the furnace.

In order to compensate for warping or distortion of the main shaft 1, due to the excessively high temperatures in the furnace, a universal bearing is provided at the lower extremity of the shaft 1. This universal bearing will allow distort-ion of the main shaft within certain limits and will still provide an efficient support for the shaft and the elements carried thereby.

It ,will thus be noted that With the present invention an efficient cooling system is provided and this system, together with the improved means for removing the rabble arms and of supporting the main shaft, produce a furnace which is simple, eflicient and readily repaired. It should be understood that it isnot desired to be limited to the exact details of constructionherein shown and described, for various modifications within thescope of the appended claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

l. In combination, a shaft having an opening bounded by a surface transverse to the shaft axis, Van arm detachably associable with said shaft and having a portion coactable with said surface to hold said arm in position relatively to said shaft during attachment of said arm to said shaft, and lockingmeans associable with said arm and said shaft to unite said elements, said locking means projecting beyond said opening after attachment of said arm to said shaft.

2. In combination, a shaft having an opening bounded by a surface of revolution generated about an axis transverse to said shaft, an arm detachably associable with said shaft and having an end portion coactable with said surface to hold said arm in position relatively to said shaft during attachment of said arm to said shaft, and locking means associated with said arm and engageable with a surface of said shaft to secure said arm to said shaft, said locking means projecting beyond said opening after attachment of said arm to said shaft.

3. In combination, a shaft having a transverse opening, an arm secured to said shaft at said opening, a locking bar pivoted upon and eccentrically of said arm and engageable with a. surface of said shaft, and means for urging said bar into engagement with said shaft surface.

4. In combination, a hollow shaft having an axis and an opening bounded by a surface transverse to said axis, an arm detachably associable with said shaft and having a portion coactable with said surface to hold said arm in position relatively to said shaft during attachment of said arm to said shaft, and locking means within said hollow shaft and associable with said arm and said shaft to unite said elements, said locking means projecting beyond said opening after attachment of said arm to said shaft.

5. In combination, a hollow shaft having an opening bounded by a surface of revolution generated about an axis transverse to said shaft, an arm detachably associable with said shaft and having a circular end portion coacta-ble with said surface to hold said arm in position relatively to said shaft during attachment of said arm to said shaft,

and locking means, associated with said arm,

located within said hollow shaft, and engageable with said shaft to secure said arm to said shaft, said locking means projecting beyond said opening'` after attachment of said arm to said'shaft.

6. In combination, a hollow shaft having a transverse opening, means dividing the 'i rabble arm having a cylindrical portion fitinterior of said, shaft into longitudinal conduits, an arm extending into said opening and having internal passages communicating with said longitudinal conduits, and locking means associated with said arm and engageable with a surface of Said shaft, said locking means being movable relatively to said arm to such a position that vsaid means -lies entirely in line with said opening.

7. In combination, a hollow shaft having a transverse circular opening, means dividing the interior of said shaft into longitudinal conduits, an arm fastened to said shaft at said opening and having internal passages communicating with said longitudinal conduits, and locking means associated with said arm and engageable with a surface of said shaft, said locking means being movable relatively to said arm to such a position that said means lies entirely in line with said circular opening.

8. In combination, a hollow shaft having a transverse opening, means dividing the interior of said shaft into longitudinal conduits, an arm having an end extending into said opening .and having internal passages communicatlng with said longitudinal conduits, a locking bar pivoted upon and eccentrically of said arm and engageable with a surface of said shaft, and means for ur ing said bar into engagement Wit said s aft surface. l

9. vIn combination, a hollow shaft having a transverse circular opening through the wall thereof, means dividing the interiorv of said shaft vinto longitudinal conduits, a

ting said circular opening and having internal passages communicating with said longitudinal conduits, and a locking bar pivotallyl mounted upon said arm and engageable with an inner surface of said shaft, said locking bar being movable relatively to said arm to such a position that said bar lies entirely in line with said circular opening. 4

10. In combination, a .hollow shaft having a .transverse circular opening through the wall'thereof, 'means dividing the interior of said shaft into longitudinal conduits, va rabblearm havingav cylindrical portion fitting said circular' opening and avingl internal passages communicating withl said longitudinal conduits, a lockin bar pivoted upon and eccentrically of said arm and engageable with an inner surface of said shaft, andV means for urglin said bar into engagement with said s a t surface.

11. Incombination, an upright shaft, a plurality of rabble arms secured to said shaft, and a fire-proof mantle covering the lower portion of said shaft only.

12. In combination, a hollow uprigh shaft, means dividing the interior of said shaft into longitudinal conduits, a plurality of rabble arms secured to said shaft and 'having internal passages communicating with said conduits, and a fire-proof mantle covering the lower portion of said shaft only.

13. In combination," a hollow upright shaft,J 4means dividing the interior of said shaft into longitudinal conduits, a plurality of rabble arms secured to said shaft and having internal passages communicating with said conduits, a furnace wall inclosing said shaft and said arms, means operablel arm to lock said arm into said opening,

shaft at said opening, a locking bar pivoted upon and veccentrical of said arm and engageable with surfaces of said shaft and of said arm to lock said arm'to said shaft, and means for urging said bar i-nto engagement with said shaft and arm surfaces.

17. In combination, a shaft havin a f transverse opening, an arm extending into said shaft opening, locking means pivotally associated with said arm and engageable with surfaces of said shaft and of said arm to lock said arm to said shaft at said opening, means for limiting the extent of'movement of said bar about its pivot, and means for urging said bar into engagement with said shaft and arm surfaces.

In testimony whereof, 4the signature of the inventor is affixed hereto.

,'HENRY ALINDER. 

